Shivam Joshi, MD

The Fine Print of the Keto Diet: Harms and Failures

The keto diet has been widely promulgated as an effective therapy for the treatment of diabetes and weight loss with minimal side effects. Many discussions regarding the diet present an unbalanced view, often omitting studies that show harm or lack of a benefit. To balance the narrative, I’ve written this post that I intend to keep maintained for foreseeable future. Below I present the links to references of important studies that are often excluded from the discussion of ketogenic, and by association, low-carbohydrate diets. I invite you to look through them. Personally, I did not expect to find as much as I did (and certainly not so many concerning side effects). If you have other studies or comments, please post them below in the reply section of this page. You can also share them with me on Twitter @sjoshiMD.

Finally, further illustrating the point of the decreasing difference between glycemic levels as time goes on (likely a result of difficulty of complying with the diet and lack of any effect on the pathophysiology of diabetes), a meta-analysis of randomized-controlled trials lasting a year did not show any benefit in fast plasma glucose or glycosylate hemoglobin levels

The claims of abundant weight loss are not substantiated with high-quality research

What is the point to the diet if there is only 2 pounds of weight loss after one year?

To put this in perspective, this is the amount of weight you would lose if you ate 19 less calories per day for an entire year (roughly).

Mutation Among Inuit to Avoid Ketosis

The Inuit of the Arctic consumed a diet high in fat given their dependence on marine mammals with blubber and high amounts of adipose tissue. One would expect that this type of diet, given the lack of carbohydrates, would induce ketosis. However, the Inuit of Greenland and Canada actually have a mutation to avoid ketosis.

The mutation can have deleterious consequences if the Inuit are not able to obtain energy from other sources since ketone bodies are a source of energy. Unsurprisingly, the mutation increases the risk of hypoketotic hypoglycemia, which increases the risk of death, especially in infants.

The plot thickens: Despite the deadly risks of the mutation, more than 80% of Greenland and Canadian Inuit have the mutation. Why? Why would evolution favor the propagation of a deleterious mutation? The only reason is if the alternative was worse.

Some have theorized that ketosis is not likely a wise a long-term strategy for survival. The ketogenic diet can cause metabolic acidosis (see below) from the production of acidic ketones, which lowers the pH. In times of stress (like illness, trauma, starvation, cold weather?, etc.), the blood can become even more acidic (lower pH) and increase the risk of death. Situations like this might have favored the spread of a mutation to circumvent ketosis in the Inuit.

Claim that the Ketogenic Diet Drastically Increases Metabolism

Keto enthusiasts often tout the diet as unique because of its ability to significantly increase the metabolic rate. Not only is this not true, in some cases, it is actually the opposite of what was found in scientific studies.

Researchers at the NIH have shown that low-fat diets (like a whole-foods plant-based diet) actually result in more fat loss than low-carb diets (e.g. the keto diet).

The low-carb diet did lose more total weight but this study shows that this weight was from lean tissue (muscle) loss and water loss, and not loss of fat (the opposite of what is generally desired).

Other studies have also shown the sizable amount of water lost with the ketogenic diet, which is regained once the ketogenic diet is stopped.

It has been hypothesized that the ketogenic diet can increase energy expenditure by a whopping 400-600 calories per day. In a scientific study, researchers found that the increase energy expenditure in the ketogenic diet was much smaller and approached the limit of science to detect the increase. In addition, fat loss was lesscompared to those on a high-carb diet. Finally, those eating a ketogenic diet had more water and lean body mass loss than those eating a low-fat, high-carb diet.

Documented Side Effects of the Ketogenic Diet from the Pediatric Epilepsy Literature